1. Field of Invention
The present invention relates to a field of mechanical equipment for packaging of food, medicine, and etc., and more particularly to a tunnel type sterilizing dryer.
2. Description of Related Arts
Tunnel type sterilizing dryers are frequently adopted in industry of packaging machinery for food, pharmacy and etc. Taking pharmacy packaging machinery as an example, transmitting mesh belt is usually adopted in a tunnel type sterilizing dryer to transmit medicine bottles. When a tunnel drying oven is handing over with other equipments, a transition plate is often adopted for connecting. The medicine bottle is transmitted on the transition plate by friction driving. If a large number of medicine bottles are in the tunnel type sterilizing dryer, sufficient friction thrust can be supplied to push the bottles on the transition plate. However, when the process is completed, as the number of medicine bottles on the transmitting mesh belt of the dryer decreasing, the friction thrust that promotes medicine bottles on the transition plate decreases accordingly. When the friction between the mesh belt and a bottom of the medicine bottle is less than the friction while the medicine bottle is on the transition plate, sliding friction occurs between the mesh belt and the bottom of the medicine bottle. Thus, small number of medicine bottles always remain on the transmitting mesh belt and the transition plate in the end. If the medicine bottles are pushed out in a manual way, the sterilized medicine bottles are contaminated again. If a bottle pushing plate having big weight is provided at the end line of the medicine bottles to promote the medicine bottles, the medicine bottles can be pushed out from the dryer. However, due to the big weight and bad heating effect of the bottle pushing plate, it is difficult to sterilize or eliminate pyrogen from the bottle pushing plate. So after entering a cooling space, the bottle pushing plate contaminates the sterilized medicine bottles. Further more, friction between the medicine bottles and the transition plate generates dust or particles polluting the environment, and also generates scratches at the bottom of the medicine bottle, which have a bad effect on the appearance quality of the medicine bottles.